BEDFORD, N.Y. -- Mary Richardson Kennedy’s family has hired an investigation firm to look into her death, The New York Post reported Sunday.

In the months after the estranged wife of Robert F. Kennedy Jr. committed suicide at her Bedford home, the Post reported, high-powered Washington, D.C. firm Investigative Group International (IGI) assigned Gary Fishman, a former Manhattan assistant district attorney, to lead a probe into many “unanswered questions” surrounding the case, according to sources interviewed by the firm following Kennedy's May 16 hanging death.

The Richardson family has not filed a wrongful-death lawsuit against the son of the late Sen. Robert F. Kennedy, according to The Post.

IGI, the Richardson family and RFK Jr. all declined to comment for The Post's story, although an IGI receptionist said that Fishman left the firm in September.